Gauging apparatus for testing parallelism



Dec. 19, 1950 A. G. ROSE ETAL GAUGING APPARATUS FOR TESTING PARALLELISM Fi'l ed July 7, 1945 2 Sheets-Sheet 1 mOE Dec. 19, 1950 .Filed July 7, 1945 A. G. ROSE EI'AL GAUGING APPARATUS FOR TESTING PARALLELISM 2 Sheets-Sheet 2 INV TORSI .Gv K.H.

'LLS.

TTORNEYS.

Patented Dec. 19, 1950 GAUGING APPARATUS FOR TESTING PARALLELISM Alfred German Rose, Gainsborough, and Kenneth Howard Nicholls, Freshford, England Application July 7, 1945, Serial No. 603,608 In Great Britain April 3, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires April 3, 1964 2 Claims.

This invention relates to the gauging at different angles of the parallelism of two or more articles arranged to pivot simultaneously in parallel relationship. An example of such a parallel motion apparatus is to be found in ihg gunor gun assembly and the sighting arm of a gun mounting in which the sighting arm is connected to the gun or gun assembly for parallel motion by linkage or equivalent means. Such a gun mounting is described in United States patent application No. 516,651, filed January 1, 1944, of Alfred German Rose, to which reference may be made for further details. It will be understood that, for purposes of clarity of description, the slight deviation from parallelism consequent upon the harmonization of the sight and guns in such an example is ignored when describing the movement of such mechanism as parallel motion.

It will be seen that, when two members are pivotally mounted on different centres and connected by linkage, it is extremely difficult to ensure, within commercial manufacturing limits, that the various centre distances in the linkage are, in the finished apparatus, within the fine limits necessary to produce parallelism in the two members at all angles especially when, in the case of a gun mounting, the effects at long ranges have to be considered.

It is with this difiiculty that the invention is concerned and it is an object of the invention to provide an apparatus for gauging the parallelism of given longitudinal axes in two or more pivoted members arranged as described above that will facilitate the adjustment of the linkage to compensate for any discrepancy in the dimensions of the various members constituting the linkage.

According to the invention, therefore, there is provided an apparatus for gauging the parallelism of given longitudinal axes in two members arranged simultaneously to pivot about parallel axes with said longitudinal axes in parallel relationship, comprising a support adapted for attachment to the first pivoted member in a definite position, and a gauging sight arranged on the support with its line of sight lying parallel to the given longitudinal axis of the first pivoted member when the support is in position on the first pivoted member and at a normal distance from such axis equal to the normal distance between the given longitudinal axes of the two pivoted For the purpose of this description, the term sight as used herein is intended to mean any device having a fixed axis defined by two points that enable the fixed axis to be lined up with one of the axes to be gauged. For example, the term sight embraces a gun sight of the reflector type, a small bore tube of a length that is substantial in comparison with the bore, or even two small spaced sighting members similar to those used on a rifle.

The invention is particularly useful in its application to the setting of the sight in relation to the guns in gun mountings of the kind described in the specification mentioned above.

In the example specifically described in that specification, the ivotal centres of the sighting arm and the gun assembly are not in vertical alignment with reference to a horizontal datum line and for this reason the normal distance between the line of sight and the axis of the guns varies to a different extent on the two sides of the horizontal position during pivotal movement of the guns.

In such a case there may be provided a gauging member, which may be conveniently located from the gun barrel, comprising several sights all arranged in vertical alignment with their axes parallel to the axis of the gun barrel but at different distances from the axis of the gun barrel. The sights may be standard reflector sights, or there may be several transparent reflectors, of the kind used in reflector sights, arranged one above the other, and a single lens tube arranged to project an image of a gratlcule on to the several reflectors simultaneously, all the reflectors being inclined at the same angle to the axis of the lens tube.

A simple form of gauging apparatus according to the invention in the form of a sight-setting device will now be described in greater detail with reference to the accompanying drawings in which:

Figure 1 is an elevation of the sight-setting device,

Figure 2 is an end view of the apparatus shown in Figure 1,

Figure 3 is a plan view of part of the apparatus shown in Figures 1 and 2, viewed in the direction of the arrow in Figure 1, and

Figure 4 is a diagram illustrating the sightsetting device in use in setting the sight of a gun turret similar to the one described in the specification mentioned above.

The sight-setting device in this example is intended for use in setting the sight in relation to the guns in a gun mounting of the kind described in the above-mentioned specification. It will be understood, however, that the device, by suitable modification, can be readily adapted for a similar purpose in connection with other gun mountings where the sight is carried on a sighting arm mounted independently of the guns.

The sight-setting device consists essentially of a supporting frame II and a sight tube I2. The frame II is formed with a pair of bosses I3 the axes of which are disposed apart by an amount equal to the distance between the axes of the two guns I4 in the gun mounting. The frame II is attached to the guns I4 by means of a pair of studs I6 secured one in each boss I3 and provided with a shank I'I extending into the bore of the guns I4. The studs I6 are secured against the ends of the barrels by means of hand wheels I8 screwed for engagement with an external thread on the end of the gun barrel (normally intended for attaching the flash eliminator), the hubs of the hand wheels being provided with recesses I9 for the accommodation of flanges 2I on the studs I6 and end caps 22 for nipping the flanges 2I against the ends of the gun barrels. The frame II is thus located from the gun barrels and securely held in a definite position in relation to the axes of the guns. The general plane of the frame Il extends at right angles to the axes of the studs I6 (and thus 3 the axes of the gun barrels), and the sight tube I2 i attached to the frame II with its axis extending at right angles to the plane containing the axes of the studs IS, a web 23 being provided on the frame I I for locating the sight tube I2 so that its axis also lies at right angles to a line joining the centres of the studs I6.

The sight tube I2 consists of four walls 24, 26, 21 and 28, the walls 24 and 21 being provided with slots 29 inclined at 45 degrees to the axis of the tube. Secured in each pair of slots 29 by means of a wedge plate 3| is a transparent reflector 32 of the kind used in reflector sights. Secured at the base of the sight tube I 2 by means of a clamp 33 is a lens tube 34 arranged with its axis coincident with the axis of the sight tube I2. The lens tube 34 is provided with a lamp house 36 and is of the well-known construction used in reflector sights. The lens tube 34 is arranged to project a graticule on to the three reflectors 32 simultaneously, the reflectors thus reflecting three images of the graticule along parallel lines of sight. Apertures 35 are provided in the walls 26 and 28 to allow the reflected images to be transmitted along the lines of sight. This construction, therefore, is equivalent to three separate reflector sights with their reflectors occupying the same positions as the reflectors 32. The different distances of the reflectors 32 from the plane containing the axes of the studs I6 are determined by the different angles of the guns and line of sight in elevation that are adopted for sight-setting purposes, as will be described more fully with reference to Figure 4. Once such distances are determined, a convenient method of checking the parallelism of the lines of sight of the reflectors 32 and the axes of the gun barrels is to take a sighting board having a datum line arranged in a plane containing the axes of the gun barrels and sighting marks at distances from the datum line corresponding to the chosen distances of the reflectors from such plane. board placed at a substantial distance from the With the sighting.

guns and the sighting device located in the gun barrels, therefore, it will be seen that the re flectors may now be finally secured with their lines of sight in alignment with their respective sighting marks on the sighting board when the lines of sight of the three reflectors will be in parallel relationship with each other and the axes of the gun barrels. It will be understood that,'once such setting operation has been performed, no further setting is required in the device for use on any given design of gun mounting.

The sight setting operation will now be described with reference to Figure 4 which illustrates diagrammatically a gun turret similar to the one described in the specification mentioned above to which reference may be made for further details if required.

Briefly, the operation of the oil motors controlling the elevation motors is brought about by a sighting arm 4I through parallel motion linkage generally indicated by reference numerals 42 and 43.

In this gun mounting the pivotal centres 44 and 46 of the gun I4 and sighting arm 4 I, respectively, are not in vertical alignment with reference to a horizontal reference plane, and for this reason, as will be readily seen from Figure 4, the normal distance between the line of sight 4'! of the sight 48 carried by the sighting arm M and a plane containing the axes 49 of the guns I4 varies to a different extent on the two sides of the intermediateposition shown in full lines. This being the case, such normal distances are determined for three different positions of the gun mounting in elevation, referred to for convenience as the intermediate position (shown in full lines) and the positions of maximum elevation and depression (shown in chain-dotted lines). The sighting device with its reflectors 32 set at the distances determined as described above is then secured in the barrels of the guns I4 and the guns moved to the position of approximate maximum depression. In this position the sight 4B is adjusted on the sighting arm 4I until its line of sight is coincident with that of the lower reflector 32, i. e., until the image of the graticule reflected by the sight 48 coincides with that reflected by thereflector 32. The guns are then elevated to the position of maximum elevation and the line of sight of the sight 48 checked on the upper reflector 32, If the image reflected by the upper reflector 32 is not coincident with that reflected by the sight 48, the two lines of sight are brought into coincidence by adjusting the length of an arm 5| extending from the sighting arm 4| and connecting it to the rod 42. The guns are then depressed into the intermediate position and if the image reflected by the intermediate reflector 32 is not coincident with that reflected by the sight 48, the length of the rod 42 connecting the arm 5| to the associated linkage is adjusted to bring the lines of sight into coincidence. If adjustment to the length of the rod has been necessary, the guns are once more depressed into the position of approximate maximum depression and the sight 48 finally adjusted on the sighting arm 4I until its line of sight is coincident with that of the lower reflector 32.

It will thus be seen that, by these means, any slight discrepancies in the dimensions of the linkages are corrected in a simple and efficient manner, and it is found that the line of sight of the sight 48 is, for all practical purposes, in correct parallel relationship with the axes of the gun vans all itUUi f l barrels at any position Of elevation or depression of the guns.

It will be understood that the distances of the various reflectors from the plane containing the axes of the studs 16 are not critical since, once the reflectors are set to an approximate position, they each correspond to a certain angle of elevation which is readily found by elevating or depressing the gun mounting until the image reflected by the particular reflector 32 is found to be coincident with that reflected by the sight 48.

The graticule contained in the lens tube 34 is conveniently provided with a small ring the diameter of which constitutes the allowable deviation from coincidence of the line of sight the sight 48.

Whilst in this example three reflectors 32 are shown, it will be understood that a greater number may be used if desired depending on the attendant circumstances.

After the line of sight of the sight 48 has been adjusted in the above manner, it may be readily harmonized with the guns M for any chosen range. If desired, however, the reflectors on the sight-setting device may, instead of being set in exact parallel relationship, be suitably inclined so that their lines of sight converge with the axes of the gun barrel at a chosen range of harmonization so that, upon adjustment of the sight 48 in the manner described above, harmonization of the sight is effected at the same time.

We claim:

1. Apparatus for gauging the parallelism of given longitudinal axes in two members arranged for pivotal movement about parallel axes and connected by adjustable parallel motion linkage so that said longitudinal axes remain in parallel relationship, comprising a support adapted for attachment to the first pivoted member in a definite position, at least two gaugin sights in the form of transparent reflectors arranged on the support with their lines of sight lying parallel to each other and to the given longitudinal axis of the first pivoted member at definite positions each corresponding to the normal distance between the given longitudinal axes of the -two pivoted members when in a predetermined position, and a single lens tube arranged to throw animageof agraticnle onto the several'reflectors simultaneously jqllg ,sevgra refl rsopeine arranged in alignment with the axis of the lens tube and inclined at the same angle thereto.

2. A sight setting device for gun mountings of the kind in which the sighting member is arranged for pivotal movement about an axis parallel to the pivotal axis of the gun and connected to the gun by adjustable parallel motion linkage so that the axes of the sighting member and gun remain in parallel relationship, said device comprising a support arranged to be located from the axis of the gun barrel, at least two gauging sights in the form of transparent reflectors arranged on the support with their lines of sight lying parallel to each other and to the axis of the gun barrel at definite positions each corresponding to the normal distance between the line of sight of the sighting member and the axis of the gun barrel when in a given sight-setting position so that the line of sight of the sighting member will be coincident with that of any given gauging sight when the axis of the gun barrel is parallel to that of the sighting member when in the sight-setting position corresponding to the position of the given gauging sight, and a single lens tube arranged to throw an image of a graticule on to the several reflectors simultaneously, the several reflectors being arranged in alignment with the axis of the lens tube and inclined at the same angle thereto.

ALFRED GERMAN ROSE. KENNETH HOWARD NICHOLLS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,295,075 Sheppard Feb. 18, 1919 1,994,177 Nolan Mar. 12, 1935 2,401,980 Smith June 11, 1946 2,464,209 Brown Mar. 15, 1949 FOREIGN PATENTS Number Country Date 14,250 Great Britain 1909 17,089 Great Britain 1905 17,371 Great Britain 1908 200,683 Great Britain July 19, 1923 

